1. Field of the Invention
This invention discloses a new process for the efficient pollination of crops by insects, primarily the production of pollinating insects in sufficient and reliable numbers so a timely introduction of these pollinating insects among flowering plants produces a crop.
2. Background Art
Plant pollination by the honeybee (Apis mellifera) is by far the most commonly recognized means of crop pollination throughout the world. This pollination method depends on a single key element in the honeybee's natural history, this insect's social characteristics which give rise to the beehive. Because the beehive is the essential center of the any honeybee's existence the entire hive of 20,000 to 40,000 bees can be controlled by manipulation of the hive such as physically moving it about to pollinate crops. In the United States about two million honeybee hives are transported around the county each year in a migratory pattern that follows the bloom of those crops that benefit from pollination. Tractor-trailer rigs with one to two thousand hives move north and south with forklifts in tow to load and unload the heavy pallets stacked with hives. They move from freeway to county road to orchard or field to place their hives for a few days before reloading and moving on to the next contract location. Disruptions to a smooth flow of business by accidents, weather, and other such delays are common. A muddy field often restricts the optimum placement of unwieldy hives throughout an orchard or prevents their removal when scheduled. A single hive weights 37 to 54 kilograms (80 to 120 pounds) and occupies about 0.25 cubic meters (9 cubic feet), filled with bees they are an unstable load even in good conditions. Wet, cold weather in a region frequently delays the need for the hives for weeks and given that the beekeeper has future contracts already scheduled the hives are pulled early to honor the next location's contract requirements before the current contract's needs are fully met. Alternatively the next region is experience warm, sunny weather and the bloom is well advanced before the hives arrive from their last contract site. Such circumstances lead to inevitable contract disputes and conflicts between parties. Equally disruptive is the time dependent necessity of the grower to employ pesticides to prevent crop damage. While the honeybees are flying the application of many pesticides means death to them and the destruction of their hives; the beekeeper's livelihood can be wiped out by one bad application even by an application in a nearby field not even the subject of the contract. Application of pesticides and the destruction of hives are another continual source of conflict between beekeepers and the growers. The honeybee and its migratory hive are vulnerable to many uncontrollable operational circumstances.
The most vexing current challenge facing beekeepers is with the bees themselves, specifically diseases and pests within the hives. With the advent of the tracheal (Acarapis woodi) and varroa (Varroa jacobsoni) mites in the United States in the 1980's, together with past highly destructive diseases such as foulbrood, the modern hive is only kept alive through continuous applications of powerful medications. Despite these efforts the USDA Bee Research Laboratory in Beltsville, Md. has charted a 25% decline in the nation's population of managed honeybee hives in just the last decade. Disease and related problems have become so rampant that states have formulated regulations against entry of diseased and pest ridden hives. However, the laws are essentially unenforceable given the manner in which the hive loads are transported (huge compact loads of stinging bees, under netting, in the dark, on tight schedules), the availability of trained personnel to diagnose problems (no funding, no recourse), and the overwhelming absolute need for bees to pollinate crops. Despite the best intentions of many parties the requirement for pollination supercedes concerns over the spread of bee diseases, parasites, and predators. From the hive the free-roaming workers come and go from the fields gathering honey and pollen, sharing the field's bounty with other bees from other places; this free interaction also brings to the hives diseases, predators and parasites which establish themselves within the structure and their populations. The incessant flow of hives around the nation carries within it a reservoir of disease and pestilence continually infecting and re-infecting the hives of other colonies also joining the migration. Additionally, local hives in the migration's path are infected, as are the natural bees of the region such as solitaries who have little natural defense against such an assault. Near extinction of native solitaries, semi-solitaries and feral social bees has occurred in much of North America due to diseases, pests, habitat fragmentation and pesticides; Buchmann and Nabhan, 1996). Further, the twin practices of heavy medication and hive migration are giving rise to new antibiotic resistant bacterial infections and viruses which are being quickly dispersed by the finest highway system in the world. Yet the honeybee hive migration continues because pollination is a necessity to the orchardist and farmer raising any of the over ninety United States crops significantly benefiting from commercial honeybee pollination. The grower's economic survival is simply at issue. And no less a demand comes from the consuming public whose every third mouthful of food is dependent on pollination.
Modern agricultural practice requires the intensive cultivation of the land for a massive single crop to be an economically viable operation, the migratory hive pollination system is simply a workable response to this requirement. Hives are brought to the apple orchard or sunflower field to perform a single vital service over a few days time and then must be removed for the continued cultivation of the crop. If the hives remained they would either be poisoned by insecticides or shortly starve to death because no forage is available after the crop flowering is complete. Given no viable alternative pollination system the honeybee hive developed to supply honey has been drafted into use as the migrating pollination component within the manufacturing system of modern agriculture. The honeybee hive has become a necessary tool used once annually and sent away until needed a year hence. But the honeybee and its hive are organic, active organisms with continual significant demands which poorly adapt to quick, heavy uses followed by long-term storage. The fit of the honeybee hive for pollination is not nearly right the nation's agricultural is modeled on an industrial paradigm where the manufacturing flow of crop production continually stumbles over the ill-adapted and expensive handicraft component of hive-based pollination. Yet the migrating honeybee hive is the most successful commercial pollination system in the United State despite all of its drawbacks because there is no significant alternative.
There is a second much smaller insect-based commercial pollination system that utilizes the solitary bee for production of a very few commercial crops. Solitary bees are of the same Hymenoptera order as honeybees, but represent considerably more biological diversity as they have adapted to many widely varying pollination requirements. Solitaries are represented by some 3500 species in North America alone and over 25,000 worldwide compared to only seven species of honeybees of which only two are used commercially. The solitary differs radically from the honeybee in that they have neither a social structure nor a hive. Instead each female mates, builds her own nest in a cavity, provisions it with food, lays her own eggs, and dies all in the space of a few weeks time (Batra, 1984; Free, 1993). A few solitaries have been studied extensively to determine how they might be utilized as crop pollinators (Torchio 1987, 1991). Some of those studied include the mason bee (Osmia lignaria), hornfaced bee (Osmia cornifrons), alfalfa leafcutter bee (Megachile rotundata), alkali bee (Nomia melanderi), and the fuzzyfoot bee (Anthophora pilipes). A wide variety of techniques and trials have been conducted to ascertain their effectiveness for commercial applications. Mason bees have proven to be a particularly good pollinator of almonds in the United States (Torchio, 1981, 1991; Batra 1982). Mason and hornfaced bees have also proven a superior pollinator of apple orchards (Kuhn and Ambrose, 1984; Torchio, 1985, 1987). Additionally the fruits pollinated by Osmia have more fully developed seeds, which provide more hormones and resulting flavor, and a better shape (Torchio, 1987). In Japan hornfaced bees have been used commercially for pollination of fruit trees for many years. In Denmark the hornfaced bee has been used to pollinate greenhouse crops. Many solitaries have proven exceptionally good pollinators, far superior to the honeybee in percentage of blossom sets, speed of sets, and overall crop benefit.
The most commercially successful solitary pollinator is the leafcutter used in alfalfa seed production in North America. The problems faced by the leafcutter and mason bees are illustrative of those faced by solitaries introduced as an alternative pollinator for honeybee (Peterson et al., 1992; Griffin 1993). Nearly all the problems that prevent the solitary from becoming an effective commercial pollinator stem from its life cycle survival strategies. Most solitaries do not have gregarious nesting sites but instead seek out obscure, widely spaced cavities suitable for nests to evade the numerous predators and parasites that feed on their eggs and foodstuffs. This hiding and dispersal technique also minimized the spread and contamination by fungi and pathogens. Those solitaries with gregarious nesting habits typically have very short flight ranges and nest in relatively inhospitable environments such as the alkali flats of the alkali bee (Buchman and Nabnan, 1996). Few or no natural pests and pathogens existed in these remote, relatively sterile, isolated environments. Whether alone or in isolated colonies the solitaries were in balance with their few natural diseases and pests until agriculture disrupted their nesting sites and alien insects and pathogens entered their domains. Those solitaries which do exhibit a gregarious nesting habit--such as the leafcutter and mason bee--and are lured into small areas by artificial nesting sites so they may be managed are plagued by these natural and introduced forces which advantage themselves of such unnaturally high concentrations of easy prey. For example, the fungus Ascosphaera aggregata produces a chalkbrood disease specific to Megachilidae. The rate of infected larvae dead before reaching maturity can sometimes reach colony losses of 50% to 100% from year to year. Various management practices utilizing disposable nesting materials and powerful fumigants are used to treat this common pathogen (Goerzen, 1992; Mayer, 1988, 1990). Mason bees are similarly afflicted by another fungus Ascosphaera torchioi (Torchio, 1992). A second important problem solitary management faces is parasitism and predation. Some eight parasitic species and twenty-eight predator or nest destroyer species infest leafcutters or their nest sites; (Waters, 1980). Near total loss of a leafcutter colony can result form a heavy infestations of such opportunistic feeders from the genera of Pteromalus, Monodontomerus, Tetrasttichus and Melittobia. The mason bee experiences particularly heavy depredation by the Stelis montana bee and tiny Chalcid wasps, both of which lay their eggs in the mason's nesting site and heavily parasitizes the developing larva. Since the propagation rate of these parasitoids is typically many times that of the solitaries, managed clustering of nesting sites even with substantial efforts to control parasites and predators usually results in a total loss of a colony in closely packed nesting holes the following years. A third problem is the relatively few progeny solitary bees produce. The honeybee queen, protected and nurtured by the hive society, can produce thirty thousands egg a season whereas the solitary mason bee female only produces perhaps thirty, the leafcutter in field conditions about fifteen. The loss of even a few solitary eggs has a major impact on the next season pollination cycle and because of the sealed cocoon it is very difficult to determine how many viable adults will emerge for pollination. These problems are at the core of why solitaries have not found a major role in commercial crop pollination. Simply stated, their numbers fluctuate so greatly from year to year and place to place the can not be relied upon even under current best methods of management to be available and sufficient when needed. No grower can even consider this magnitude of uncontrollable risk in their operation. Alfalfa seed production has been the only commercial crop where a solitary has proven successful because honeybees are ineffectual pollinators of alfalfa whereas leafcutter bees have proven to be one of the very few species undeterred by the unusual tripping mechanism found in the alfalfa flowers. Due to this unique factor alone the extra care and expense required to manage leafcutters for greatly enhanced alfalfa seed production has proven justifiable. Unfortunately, the leafcutter has proven to be an ineffectual pollinator of any other significant crop and the mason bee has failed to reliably propagate for commercial purposes. All other solitaries share one or more of these or similar faults for similar reasons. Solitary pollination has not found any other significant commercial crop where the expense necessary for reliable, timely delivery of sufficient numbers of solitary pollinators has been lower than existing costs for the comparable process of migratory honeybee pollination.
By far the most significant expense element in producing solitary pollinators has been the costs associated with their successful propagation. A variety of techniques have been utilized in the past but they are all variations on a single common propagation method used to establish a form of pollinator management--providing an open artificial nesting site to collect solitaries for the next pollinating season. By attracting free-ranging (wild) solitaries to a open artificial nest in high-density numbers in some form of device from which the cocoons can be removed for use elsewhere, a system of solitary pollination has proven economically possible as demonstrated by the leafcutter and alfalfa seed crop. Several United States patents have well established the art of open artificial nest propagation for free-ranging (wild) solitaries. An early patent disclosed a simple layering of grooved wooden blocks held together by a bolt (Barber U.S. Pat. No. 3,936,894). A more practical design utilizing individual waxed paper tubes based on an old Japanese country custom utilizing bundled reeds followed (Norman, U.S. Pat. No. 4,365,372). More efficient designs for cocoon recovery based on an unwinding spiral nest configurations soon were issued (Weiderrich U.S. Pat. Nos. 4,293,966 and 4,319,371; Youssef U.S. Pat. No. 4,491,994). Disposable and mobile nesting box designs have been claimed in the most recent art (Pederson U.S. Pat. No. 4,628,558; Norman U.S. Pat. No. 4,716,609; McCarthy U.S. Pat. Nos. 4,765,007 and 5,591,063; Trafford U.S. Pat. No. 5,403,226; Mills U.S. Pat. No. 5,618,220). These patents represent the current state of U.S. patent art and all share the common feature of capturing the progeny of free-ranging (wild) solitary bees so the next generation of emerging adults can be used for crop pollination. A common practice now in use employs clusters of individual paper tubes to facilitate removal of nested cocoons. These tubes are bundled for placement in permanent sheds or mobile wagons located in the fields. Following the nesting season the tubes are removed from the field, opened, the cocoons obviously parasitized or diseased or dead discarded, and the few remaining solitaries kept and stored. The kept cocoons contain prepupae or imagoes in diapause and in this form they are sold by the liter or gallon to growers and providers of pollination services (Peterson et al, 1992). Because the condition of the solitaries inside any batch of unopened cocoon is unknown as to the sex ratio (only females are effective pollinators), viability due to disease or predation, and other health concerns such as fungi, samples are submitted for analysis to qualified fee-for-service laboratories such as the Canadian Cocoon Testing Center (Murrell, 1997). Given the magnitude of disease and predation among open artificial nesting no grower can afford not to have an offering of pollinating solitaries certified for quality. The most significant category of loss in raising solitaries in this manner is associated with the control of parasites, diseases, and predators. Effective control of this loss factor is a key economic component in rearing sufficient numbers of healthy solitaries and other pollinating insects so they can be reliably employed as cost effective crop pollinators.
While no closed system for rearing pollinating insects is known in prior art insect propagation technology is widely available and some patented for other purposes. Over fifteen United States patents have been issued for various apparatuses and methods in the last twenty-five year alone. Nearly all these patents put forth methods of producing insect eggs and larvae for propagation of parasitic insects, diseases, or specific insects. An early representative patent of this group (Andreev U.S. Pat. No. 3,893,420) describes capturing host eggs on a net substrata as food for parasitic insects thereby increasing the parasites numbers for use in controlling agricultural pests. A following patent (Voegele U.S. Pat. No. 4,411,220) utilized a pit and slate means for a similar purpose, producing hosts for parasitization by predatory trichogrammidae. A method for mass rearing of fruit flies (Vargas U.S. Pat. No. 4,594,964) introduced the concept of oviposting into small tubes that were flushed out with water whereby the eggs are collected. Next, a conveyor belt moving through a wasp cage upon which host eggs are inoculated with parasitic eggs was disclosed (Pizzol U.S. Pat. No. 4,765,274). More recent designs for propagating insect diseases and eaters, specifically entomopathogens and entomoparasites, made broad design and method claims all specifically concerned with producing of one or both of these objectives (Carr U.S. Pat. No. 5,113,799; Carr U.S. Pat. No. 5,178,094). The novel element of self-regulating larval spacing incorporated in an old design was advanced most recently (Hughes U.S. Pat. No. 5,351,643). None of these insect propagation patents nor any other known source describes production of pollinating insects by any techniques beyond those already detailed for the propagation of solitary bees.